DIDAC Export offer an optimum quality of Double Burette Volume Change Apparatus. The apparatus comprises two measurement tubes, which have a 25 ml burette mounted internally and an acrylic tube externally. The burette tubes are connected directly to a reversing valve system, which is used to reverse the direction of travel of the interface in the measurement tubes without affecting the direction of flow of water to or from the triaxial cell. The unit also includes a by-pass valve system when volume change measurement is not required.